Increased use of FIT could improve CRC screening rates, especially among vulnerable populations

Faecal immunochemical tests (FITs) are effective for screening for colorectal cancer (CRC) when used annually by average risk asymptomatic adults.

Because these at-home tests are easy-to-use, non-invasive, and inexpensive, adopting their use could improve lagging CRC screening rates, especially among vulnerable populations.

Findings from a meta-analysis are published in Annals of Internal Medicine.

The U.S. Preventive Services Task Force currently recommends CRC screening for adults aged 50 to age 75, without preferentially recommending one specific screening test over another.

Colonoscopy is considered to be the gold standard in the U.S., but several other countries use annual or biennial stool blood tests.

Despite colonoscopy effectiveness and cost-effectiveness, only about 65 percent of eligible U.S. adults get tested.

Adopting a FIT screening strategy could increase screening rates, but more information is needed about FIT performance for CRC detection.

Researchers from the Regenstrief Institute and Indiana University School of Medicine reviewed 31 studies involving 120,255 patients to summarise FIT performance for CRC, quantify FIT performance characteristics for colon polyps, and to identify factors affecting those characteristics.

They found that single-application FITs have moderate to high sensitivity and specificity for CRC, depending on the positivity threshold.

At a high specificity, FITs are moderately sensitive for CRC.

Although FITs are much less sensitive for advanced adenomas, these lesions rarely transition to cancer, suggesting an opportunity to detect this lesion with programmatic screening before they become cancer.

James Allison, MD, from the University of California, San Francisco and Kaiser Permanente Northern California Division of Research laments the designation of colonoscopy as the "best/gold standard" screening test when there exists a paucity of research supporting that assertion or comparing colonoscopy to less invasive, cheaper tests.

He notes that some U.S. primary care physicians and many of their patients may be unaware that FITs are noninvasive, easy to prepare, and inexpensive and have effectiveness similar to that of colonoscopy when used in a consistent programmatic fashion to screen for CRC.

This is because the media and health systems continue to promote colonoscopy as the best test for CRC, even though U.S. CRC screening guidelines no longer promote this idea.

Dr. Allison suggests that physicians in the U.S. be educated about the advantages of FITs as screening tests for CRC and educate and advocate to increase screening rates.

He also suggests that changes to insurance coverage that could lead to many more of our vulnerable populations being successfully screened.

Source: American College of Physicians